What is a Morel-Lavallée lesion?
A Morel-Lavallée lesion is a closed degloving injury that occurs when the skin and underlying fascia separate, accumulating blood, lymph, and fat in the space created. This injury typically results from high-energy trauma, such as a road traffic accident, a fall from a significant height, or sports injuries.
Morel-Lavallée lesions often occur in areas subject to shearing forces, with the proximal lateral thigh being a common site due to its susceptibility during high-energy impacts. Surgical site infections can complicate the healing process of these lesions, particularly following procedures involving the pelvis and acetabulum.
Magnetic resonance imaging (MRI) serves as the gold standard for diagnosing Morel-Lavallée lesions. MRI provides detailed images of soft tissue injuries, helping to identify the extent of fluid collection and to differentiate these lesions from other types of soft tissue injuries such as hematomas or abscesses.
Causes and complications
The primary cause of a Morel-Lavallée lesion is high-impact trauma that shears the skin and subcutaneous tissue away from the underlying superficial fascia itself. Common scenarios include motor vehicle accidents, falls, and contact sports injuries. If not properly treated, complications can include infection, chronic pain, and persistent swelling.
In some cases, the lesion can become encapsulated, forming a persistent cyst-like structure that may require surgical intervention.
Classifications
Morel-Lavallée lesions are classified based on their location, size, and duration since the injury occurred. Acute lesions are identified and treated soon after the trauma, while chronic lesions have persisted for a longer period and may have developed secondary complications such as fibrosis or infection.










